package one;

import java.util.*;
public class StringProcess {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		System.out.println("输入字符串：");
		String s = scan.nextLine();
		Set<Character> setChar = new TreeSet<>();
		for(int i = 0; i < s.length(); i++) {
			setChar.add(s.charAt(i));
		}
		Iterator<Character> it = setChar.iterator();
		while(it.hasNext()) {
			System.out.print(it.next());
		}
		scan.close();
	}
}
